78991557704280 has 1152 divisors, whose sum is σ = 291996751737600. Its totient is φ = 18407894630400.

The previous prime is 78991557704219. The next prime is 78991557704321. The reversal of 78991557704280 is 8240775519987.

78991557704280 is a `hidden beast` number, since 7 + 8 + 9 + 9 + 1 + 5 + 577 + 0 + 42 + 8 + 0 = 666.

78991557704280 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 78991557704199 and 78991557704208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 183275075665 + ... + 183275076095.

It is an arithmetic number, because the mean of its divisors is an integer number (253469402550).

Almost surely, 2^{78991557704280} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78991557704280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145998375868800).

78991557704280 is an abundant number, since it is smaller than the sum of its proper divisors (213005194033320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78991557704280 is a wasteful number, since it uses less digits than its factorization.

78991557704280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1097 (or 1067 counting only the distinct ones).

The product of its (nonzero) digits is 355622400, while the sum is 72.

The spelling of 78991557704280 in words is "seventy-eight trillion, nine hundred ninety-one billion, five hundred fifty-seven million, seven hundred four thousand, two hundred eighty".